Microsoft SkyDrive is now called OneDrive. The service is similar to Dropbox or Google Drive except that Microsoft is giving away Gigabytes of free storage space, 100 GB to be precise, to both new and existing users.

To reclaim your free space on SkyDrive OneDrive, all you have to do is visit the onedrive.com website and sign-in with your Microsoft (or Live) account. If you have happen to be among the first 100,000 users to try the new OneDrive service, the bonus space will be credited to your account.

The extra space earned through these promotions are valid for a period of one year.

Update: The 100 GB offer is no longer available but you can still add an extra 20 GB of free storage space to your OneDrive account. Go to the Manage Storage option of OneDrive and then click the Redeem OneDrive Code link. Here you can enter the code as YNQKG-KPVY3-9H4G6-B679B-QJYMC for an extra 20 GB.

Update 2: The redemption code is gone too. Your only options for getting free space are now referrals and camera uploads.

OneDrive offers apps for Windows Phone, iPhone and Android device and if you happen to turn on the camera upload function on these device, another 3 GB will be added to your account. Then there’s the Dropbox like referral model earning you .5 GB for every referral up to 5 GB.